What are colorados major highways?

Interstate 70, Interstate 76, Interstate 25, US Highway 50, US Highway 287..

I-25 is the North-South Corridor and I-70 is the East-West route.

yes

Interstate70 Colorado470 US highway6 and State highway93

The top 6 most populous (and major cities) are (in order): Denver, Colorado Springs, Pueblo, Lakewood, Fort Collins, and Aurora